1 files changed, 280 insertions, 0 deletions

diff --git a/drivers/thunderbolt/usb4_port.c b/drivers/thunderbolt/usb4_port.c
new file mode 100644
index 000000000000..29e2a4f9c9f5
--- /dev/null
+++ b/drivers/thunderbolt/usb4_port.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB4 port device
+ *
+ * Copyright (C) 2021, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/pm_runtime.h>
+
+#include "tb.h"
+
+static ssize_t link_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
+	struct tb_port *port = usb4->port;
+	struct tb *tb = port->sw->tb;
+	const char *link;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	if (tb_is_upstream_port(port))
+		link = port->sw->link_usb4 ? "usb4" : "tbt";
+	else if (tb_port_has_remote(port))
+		link = port->remote->sw->link_usb4 ? "usb4" : "tbt";
+	else
+		link = "none";
+
+	mutex_unlock(&tb->lock);
+
+	return sysfs_emit(buf, "%s\n", link);
+}
+static DEVICE_ATTR_RO(link);
+
+static struct attribute *common_attrs[] = {
+	&dev_attr_link.attr,
+	NULL
+};
+
+static const struct attribute_group common_group = {
+	.attrs = common_attrs,
+};
+
+static int usb4_port_offline(struct usb4_port *usb4)
+{
+	struct tb_port *port = usb4->port;
+	int ret;
+
+	ret = tb_acpi_power_on_retimers(port);
+	if (ret)
+		return ret;
+
+	ret = usb4_port_router_offline(port);
+	if (ret) {
+		tb_acpi_power_off_retimers(port);
+		return ret;
+	}
+
+	ret = tb_retimer_scan(port, false);
+	if (ret) {
+		usb4_port_router_online(port);
+		tb_acpi_power_off_retimers(port);
+	}
+
+	return ret;
+}
+
+static void usb4_port_online(struct usb4_port *usb4)
+{
+	struct tb_port *port = usb4->port;
+
+	usb4_port_router_online(port);
+	tb_acpi_power_off_retimers(port);
+}
+
+static ssize_t offline_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
+
+	return sysfs_emit(buf, "%d\n", usb4->offline);
+}
+
+static ssize_t offline_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
+	struct tb_port *port = usb4->port;
+	struct tb *tb = port->sw->tb;
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(&usb4->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_rpm;
+	}
+
+	if (val == usb4->offline)
+		goto out_unlock;
+
+	/* Offline mode works only for ports that are not connected */
+	if (tb_port_has_remote(port)) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+
+	if (val) {
+		ret = usb4_port_offline(usb4);
+		if (ret)
+			goto out_unlock;
+	} else {
+		usb4_port_online(usb4);
+		tb_retimer_remove_all(port);
+	}
+
+	usb4->offline = val;
+	tb_port_dbg(port, "%s offline mode\n", val ? "enter" : "exit");
+
+out_unlock:
+	mutex_unlock(&tb->lock);
+out_rpm:
+	pm_runtime_mark_last_busy(&usb4->dev);
+	pm_runtime_put_autosuspend(&usb4->dev);
+
+	return ret ? ret : count;
+}
+static DEVICE_ATTR_RW(offline);
+
+static ssize_t rescan_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
+	struct tb_port *port = usb4->port;
+	struct tb *tb = port->sw->tb;
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	if (!val)
+		return count;
+
+	pm_runtime_get_sync(&usb4->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_rpm;
+	}
+
+	/* Must be in offline mode already */
+	if (!usb4->offline) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	tb_retimer_remove_all(port);
+	ret = tb_retimer_scan(port, true);
+
+out_unlock:
+	mutex_unlock(&tb->lock);
+out_rpm:
+	pm_runtime_mark_last_busy(&usb4->dev);
+	pm_runtime_put_autosuspend(&usb4->dev);
+
+	return ret ? ret : count;
+}
+static DEVICE_ATTR_WO(rescan);
+
+static struct attribute *service_attrs[] = {
+	&dev_attr_offline.attr,
+	&dev_attr_rescan.attr,
+	NULL
+};
+
+static umode_t service_attr_is_visible(struct kobject *kobj,
+				       struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
+
+	/*
+	 * Always need some platform help to cycle the modes so that
+	 * retimers can be accessed through the sideband.
+	 */
+	return usb4->can_offline ? attr->mode : 0;
+}
+
+static const struct attribute_group service_group = {
+	.attrs = service_attrs,
+	.is_visible = service_attr_is_visible,
+};
+
+static const struct attribute_group *usb4_port_device_groups[] = {
+	&common_group,
+	&service_group,
+	NULL
+};
+
+static void usb4_port_device_release(struct device *dev)
+{
+	struct usb4_port *usb4 = container_of(dev, struct usb4_port, dev);
+
+	kfree(usb4);
+}
+
+struct device_type usb4_port_device_type = {
+	.name = "usb4_port",
+	.groups = usb4_port_device_groups,
+	.release = usb4_port_device_release,
+};
+
+/**
+ * usb4_port_device_add() - Add USB4 port device
+ * @port: Lane 0 adapter port to add the USB4 port
+ *
+ * Creates and registers a USB4 port device for @port. Returns the new
+ * USB4 port device pointer or ERR_PTR() in case of error.
+ */
+struct usb4_port *usb4_port_device_add(struct tb_port *port)
+{
+	struct usb4_port *usb4;
+	int ret;
+
+	usb4 = kzalloc(sizeof(*usb4), GFP_KERNEL);
+	if (!usb4)
+		return ERR_PTR(-ENOMEM);
+
+	usb4->port = port;
+	usb4->dev.type = &usb4_port_device_type;
+	usb4->dev.parent = &port->sw->dev;
+	dev_set_name(&usb4->dev, "usb4_port%d", port->port);
+
+	ret = device_register(&usb4->dev);
+	if (ret) {
+		put_device(&usb4->dev);
+		return ERR_PTR(ret);
+	}
+
+	pm_runtime_no_callbacks(&usb4->dev);
+	pm_runtime_set_active(&usb4->dev);
+	pm_runtime_enable(&usb4->dev);
+	pm_runtime_set_autosuspend_delay(&usb4->dev, TB_AUTOSUSPEND_DELAY);
+	pm_runtime_mark_last_busy(&usb4->dev);
+	pm_runtime_use_autosuspend(&usb4->dev);
+
+	return usb4;
+}
+
+/**
+ * usb4_port_device_remove() - Removes USB4 port device
+ * @usb4: USB4 port device
+ *
+ * Unregisters the USB4 port device from the system. The device will be
+ * released when the last reference is dropped.
+ */
+void usb4_port_device_remove(struct usb4_port *usb4)
+{
+	device_unregister(&usb4->dev);
+}
+
+/**
+ * usb4_port_device_resume() - Resumes USB4 port device
+ * @usb4: USB4 port device
+ *
+ * Used to resume USB4 port device after sleep state.
+ */
+int usb4_port_device_resume(struct usb4_port *usb4)
+{
+	return usb4->offline ? usb4_port_offline(usb4) : 0;
+}